Wiper blade for window panes of motor vehicles

ABSTRACT

A wiper blade ( 10 ) for windows of motor vehicles is proposed, which is equipped with an elastic, elongated support element for an elongated wiper strip ( 22 ), which strip comprises a flexible material and can be placed against the window ( 28 ) to be wiped with a wiper lip ( 30 ) and which on its long sides has opposed longitudinal grooves ( 34 ), in which spaced-apart longitudinal rails ( 32 ) of the support element ( 12 ) are located, which rails are secured in the grooves ( 34 ) by at least one retainer ( 36,38,40 ) that spans the spacing on the side of the support element ( 12 ) remote from the wiper lip ( 30 ). A spoiler ( 23 ) extends in the longitudinal direction of the support element, and for each retainer ( 36,38,40 ), the spoiler has a recess ( 46,48,50 ), which extends crosswise to the longitudinal direction of the wiper blade ( 10 ). The outer profile of the retainer is at least approximately adapted to the profile of the spoiler.

BACKGROUND OF THE INVENTION

In wiper blades, the support element is intended to assure the mostuniform possible distribution, over the entire field swept by the wiperblade, of the contact pressure of the wiper blade on the window, whichpressure originates in the wiper arm. Because of an appropriatecurvature of the unstressed support element —that is, when the wiperblade is not resting on the window—the ends of the wiper strip, which inwiper blade operation are placed fully against the window, are urged bythe then-tensed support element toward the window, even if the radii ofcurvature of spherically curved vehicle windows differ in each wiperblade position. Accordingly, the curvature of the wiper blade has to besomewhat greater than the greatest curvature measured in the field to beswept of the window to be wiped. The support element thus replaces thecomplicated support bracket construction with two spring rails, disposedin the wiper strip, as they are used in conventional wiper blades(German patent disclosure DE-OS 15 05 357.)

The invention is based on a wiper blade as generically defined by thepreamble to claim 1. In a known wiper blade of this type (DE 196 27115.0 A1) must be provided with a separate wind repelling strip, orspoiler, if the tendencies of the wiper blade to lift away from thewindow at relatively high travel speeds are to be averted. If thisspoiler is to be disposed on the side of the support element remote fromthe window, difficulties can arise in replacing the used wiper strip, atleast whenever this replacement is done by the end user of the wiperblade. That is, this process requires not only the replacement of thewiper strip but further installation work with regard to the spoiler.

SUMMARY OF THE INVENTION

In the wiper blade according to the invention, as defined by thecharacteristics of the body of claim 1, it is possible for this spoilerto be formed integrally and economically onto the wiper strip; therecesses make an inconspicuous, problem-free placement of the retainerspossible. Special installation steps for the spoiler are dispensed with.Because of the adaptation of the outer profile of the retainer to theprofile of the spoiler, the spoiler remains operative over its fulllength, because no gaps that impair the contact pressure distributionremain. Even edges that occur at the recesses and can lead to anundesired reinforcement of the wind noise occurring in the wiper bladeare covered by the retainers.

For attaching the wiper blade to a driven wiper arm, the retainer isdisposed in the longitudinal middle portion of the support element andis provided with means for attaching a wiper arm of this kind.

To avoid the risk of injury from the sharp-edged ends of thelongitudinal rails when a person is manipulating the wiper blade, atleast one retainer is disposed on one end of the support element and isprovided with means for covering the end edges of the longitudinalrails.

In the case of especially long wiper blades, it has proved advantageousif a further retainer is disposed between the retainer disposed in thelongitudinal center portion and the retainer disposed on the end of thesupport element, because this prevents a portion of a longitudinal railfrom snapping out of its longitudinal groove, with the attendant loss ofwiping quality.

Simple securing of the longitudinal rails in their longitudinal groovesis attained if each retainer, with at least one kt, clasps a respectiveone of the two longitudinal rails on its longitudinal edges.

To lend the retainer the stability required during operation of thewiper blade, the groovelike recess, in the spoiler is filled by a bodyof the retainer, which body has the extension.

To achieve an attractive appearance of the wiper blade, in terms of thelength of the wiper blade, the length of the retainer is adapted to thelength of the groovelike recess.

Since in the course of time the material comprising the wiper strip andthe spoiler integrally joined to it ages, which is associated with acertain shrinkage, air gaps can arise between the retainers and the endfaces, toward them, of the spoiler portions; these gaps can lead to thedisadvantages already mentioned in terms of appearance and noisereinforcement. In a refinement of the invention, this can be hindered byproviding that the retainer is provided with a wall, which extendslongitudinally of the wiper blade and which covers a peripheral regionof the spoiler, adjacent to the recess, on the back wall on the spoiler,remote from the leading-edge face.

Another possible way of overcoming the above disadvantages is obtainedif the body of the retainer, on its face end toward the recess wall ofthe spoiler, is provided with a recess, into which the spoiler plungeswith a respective end piece.

Expediently, the retainer is made from a plastic.

Further advantageous refinements and features of the invention aredisclosed in the ensuing description of exemplary embodiments, shown inthe associated drawing.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawing:

FIG. 1 is a side view of a first embodiment of a wiper blade embodiedaccording to the invention and attached to a driven wiper arm;

FIGS. 2-4 each show a plan view on variously embodied wiper bladesupport elements;

FIG. 5 is an enlarged perspective view of approximately half of thewiper blade of FIG. 1;

FIG. 6 shows a cross section through the wiper blade of FIG. 5 along theline VI—VI;

FIG. 7 shows the arrangement of FIG. 5 after ageing of the wiper stripand of the spoiler belonging to it;

FIG. 8, in a view corresponding to FIG. 5, shows another embodiment ofthe wiper blade of the invention;

FIG. 9 is a perspective view of a retainer, belonging to the wiper bladeof FIG. 8 and embodied as a connection device;

FIG. 10 is a perspective view of a retainer, embodied for covering thelongitudinal rail end edges, for the wiper blade of FIG. 8;

FIG. 11 is a perspective view of a retainer, disposed between theconnection device and the end edges of the longitudinal rails, for thewiper blade of FIG. 8;

FIG. 12 is a view corresponding to FIG. 5 of a further embodiment of thewiper blade of the invention;

FIG. 13 is a perspective view of a retainer, embodied as a connectiondevice and belonging to the wiper blade of FIG. 12;

FIG. 14 is a perspective view of a retainer, embodied for covering theend edges of the longitudinal rails, for the wiper blade of FIG. 12; and

FIG. 15 is a perspective view of a retainer, disposed between theconnection device and the end edges of the longitudinal rails, for thewiper blade of FIG. 12.

DESCRIPTION OF THE EXEMPLARY EMBODIMENTS

A wiper blade 10, shown in FIGS. 1, 5 and 6, for motor vehicle windowshas a multi-part elongated, spring-elastic support element 12, which isshown separately in FIG. 2. On the top side 14 of the support element 12pointing away from the window—whose surface to be wiped is identified byreference numeral 28—is a connection device 16, with the aid of whichthe wiper blade can be connected separably to a wiper arm 18 guidedalong the body of a motor vehicle. An elongated, rubber-elastic wiperstrip 22 is disposed, parallel to the longitudinal axis of the supportelement 12, on the underside 20 of the support element 12 orientedtoward the window. The free end 24 of the wiper arm 18 is provided withmeans known per se for separably connecting the wiper blade to the wiperarm. Corresponding counterpart connection means are provided on theconnection device 16. The driven wiper arm 18, which can be movedbetween turning points, is urged in the direction of the arrow 26 towardthe window to be wiped, whose surface to be wiped is represented in FIG.1 by a dot-dashed line 28. Since the dot-dashed line 28 is intended torepresent the greatest curvature of the window surface, it is clear thatthe curvature of the wiper blade 10, resting with both ends on thewindow but still unstressed, is greater than the maximum curvature ofthe window. Under the contact pressure (arrow 26), the wiper bladepresses with its wiper lip 30, over the entire length thereof, againstthe window surface 28. In the process, a tension builds up in thebandlike, spring-elastic support element 12 that assures a propercontact of the wiper strip 22, or wiper lip 30, over its entire lengthwith the motor vehicle window.

As FIGS. 2 and 6 clearly show, in the wiper blade of FIGS. 1, 5 and 6,the support element 12 is formed by two loose, spring-elasticlongitudinal rails 32. However, it is also conceivable either to jointhese two longitudinal spring rails 132 to one another on one end via acrosspiece 133 (FIG. 3), or to dispose one crosspiece 233, 234 on eachof the two ends of the longitudinal spring rails 232 (FIG. 4). Withregard to the invention, the only significant aspect here is that thesupport element 12 (FIG. 2) or 112 (FIG. 3) or the support element 212of FIG. 4, made preferably from spring band steel has two spaced-apartlongitudinal rails 32, 132, and 232, respectively, which belong to thesupport element or form the support element (FIG. 2).

The special feature of a first embodiment of the wiper blade of theinvention will now be described in further detail in conjunction withFIGS. 5 and 6 of the drawing—which essentially corresponds to theembodiment of FIG. 1. FIG. 6 is particular shows that the twolongitudinal rails 32 belonging to the support element 12 rest inlongitudinal grooves 34 of the wiper strip 22, which are located in acommon plane located at a spacing distance from the surface to be wipedof the windshield 28. The longitudinal grooves 34 and thus thelongitudinal rails 32 received in them are spaced apart from oneanother. To prevent these longitudinal rails 32 from being able to shifttransversely to their length out of their longitudinal grooves 34, theyare secured by a plurality of retainers, of which the first retainer 36is disposed in the longitudinal middle portion of the support element12. A further, second retainer 38 is disposed on each of the two ends ofthe support element 12, and a third retainer 40 is provided in each casebetween the first retainer and each second retainer 38 (FIGS. 1 and 5).As FIGS. 5-7 clearly show, the wiper strip 22 extends via a longitudinalstrut 42, located between the longitudinal grooves 34, as far as the topside 14 of the support element 12 facing away from the window 28. Thislongitudinal extension 23, which extends longitudinally of the wiperstrip 22 and adjoins the longitudinal strut 42 is embodied as a spoiler;that is, its side that during wiping operation is predominantlyencountered by the relative wind (arrow 25 in FIG. 6) is equipped with aleading-edge throat 44. For the retainers 36, 38 and 40, the wiper strip22, which also includes the spoiler 23, is provided, on its side of thesupport element 12 remote from the wiper lip 30, with recesses 46, 48,50 oriented transversely to the length of the wiper strip 22; of these,the first recess 46 is associated with the first retainer 36, the secondrecess 48 with the second retainer 38, and the third recess 50 with thethird retainer 40. The retainers 36, 38 and 40 span the spacing by whichthe two outer longitudinal edges 33 of the two longitudinal spring rails32 are spaced apart by one another. FIG. 6 shows this in particular interms of a third retainer 40, shown in cross section. In the region ofthe spoiler 23, the retainers 36-40 have a cross section thatsubstantially coincides with the cross section of the spoiler 23. Eachretainer is accordingly also provided with a leading-edge throat 44against which the relative wind 25 blows. Seen in cross section,accordingly, each retainer 36-40 has a profile, in the region of thespoiler, that is at least approximately adapted to the profile of thespoiler. The profile is shaped in such a way that the spoiler, and thusthe retainers 36, 38 and 40 located in the recesses 46, 48 and 50, meetthe need of the spoiler for improving the performance of the wiper blade10 in terms of lifting away from the window, even at high travel speeds.Accordingly each retainer 36, 38, 40, with its body 41, forms a fillerpiece that fills the recess 46, 48 and 50, respectively, associated withthe respective retainer. As FIGS. 1 and 5 show in particular, theretainer 36 disposed in the longitudinal middle portion of the supportelement 12 is provided with means for attaching the wiper arm 18. In theexemplary embodiment, these means are formed by a transverse bore 52,into which a pivot bolt, for instance, can be placed, which is thenengaged by the wiper arm with a counterpart pivot piece. The tworetainers 40, each disposed on one of the ends of the support element12, have a closing wall 54, which serves to cover the end edges 56 ofthe respective support elements 12, 112 and 212. All the retainers 36,38, 40, on the side of the retaining body 41 oriented toward the supportelement 12, are provided with opposed securing claws 58 (FIG. 6), eachof which clasps one of the two longitudinal rails 32, transversely totheir length, on their longitudinal edges 33 remote from one another. Itis indispensable that in the exemplary embodiment, each of thelongitudinal rails is also covered by a longitudinal band 59 of thewiper strip 22 and of the longitudinal extension 23, respectively. Thesole decisive factor is that the securing claws 58 fit over the outerlongitudinal edges 33 of the spring rails 32 and secure them in theirlongitudinal grooves 34 of the wiper strip 22. Furthermore, the securingclaws 58 also assure proper securing of each retainer 34, 36, 38 on thewiper strip 22 and thus also assure reliable positioning of eachretainer on the wiper blade 10. In terms of the length of the wiperblade 10, the length 60 of the retainer 36 and the length 62 of theretainer 40 are adapted to the length of the associated groovelikerecesses 46 and 50, respectively.

However, it has been found that when certain materials or mixtures ofmaterials are used to produce the wiper strip 22 and the spoiler 23integrally joined to it, a certain shrinkage ensues in the course of theageing process, especially in the longitudinal direction of the wiperstrip 22, and this can lead to the forming of gaps between the spoilerportions formed by the recesses 46, 48, 50 and the retainer bodies 41.Such a situation is shown in FIG. 7, taking as an example the exemplaryembodiment of the invention shown in FIG. 5. The gaps between thespoiler portions and the retainer bodies 41 are identified by referencenumeral 68. Aside from the unattractive appearance of such a wiperblade, these gaps 68 lead to considerable undesired noise of the wiperblade, which is highly irritating, especially at relatively high travelspeeds.

In order to cover these gaps 68, the body of the retainer 136—in anexemplary embodiment of the invention shown in FIGS. 8-11—is provided onits face end toward the recess wall of the spoiler with a recess 137(FIG. 9), into which the spoiler 23 plunges with an end piece 141 (FIG.8). A corresponding arrangement is provided on the second retainer 138as well, which is disposed on the ends of the wiper strip 22 or of thesupport element 12. The recess corresponding to the recess 137 isidentified by reference numeral 139 in FIG. 10. FIG. 8 also illustratesthe plunging of the end piece 142 into the recess 139. In thisembodiment, the third retainer 140 is embodied in bandlike form. Itwraps around the unsplit spoiler that extends between the two retainers136 and 138. FIGS. 9-11 also show the securing claws 58, alreadymentioned, which clasp the two longitudinal rails 32 on their outerlongitudinal edges 33.

A further embodiment, shown in FIGS. 12-15, shows another possible wayof covering the gaps 68, which is employed between the facing end facesof the first retainer 236 and with the corresponding faces of the secondretainer 238 and the spoiler, or the facing end faces of the thirdretainer 240 and the end faces, toward it, of the spoiler 23. To thatend, the back walls 45, located on the back side of the leading-edgethroat 44, of the respective retainers 236, 238, 240 are provided, ontheir peripheral regions adjacent to the respective recesses 46, 48, and58 (FIG. 1), with a back wall 242 which extends far enough in thelongitudinal direction of the wiper blade that a reliable covering ofthe gaps 68 is assured in every operating position of the wiper blade10.

It is a common feature of all the exemplary embodiments that the wiperblade 10, on the top side of the support element 12 opposite the wiperlip 30, is provided with a spoiler 23, extending in the longitudinaldirection of the support element, and this spoiler has one recess 46, 48and 50 for each respective retainer 36, 38, and 40, the retainerspreferably being made of a plastic, which extends crosswise to thelongitudinal direction of the wiper blade 10, and when seen in crosssection, the outer profile of the respective retainer, located in theregion of the spoiler 23, is at least approximately adapted to theprofile of the spoiler.

What is claimed is:
 1. An elongated wiper blade (10) for windows ofmotor vehicles, having an elastic, elongated support element for anelongated wiper strip (22), which strip comprises a flexible materialand can be placed against the window (28) to be wiped with a wiper lip(30) and which on its long sides has opposed longitudinal grooves (34),in which spaced-apart longitudinal rails (32) of the support element(12) are located, which rails are secured in the grooves (34) by atleast one retainer (36, 38, 40) that spans a spacing between sides ofthe support element (12) remote from the wiper lip (30), characterizedin that the wiper blade (10), on the side of the support element (12)opposite the wiper lip (30), is provided with a spoiler (23) having anouter profile, extending in the longitudinal direction of the supportelement, and for each retainer (34, 36, 38), the spoiler has a recess(46, 48, and 50, respectively) receiving said at least one retainer,which recess, extends crosswise to the longitudinal direction of thewiper blade (10), and in transverse cross section, an outer profile ofthe at least one retainer located in the region of the spoiler (23) isat least approximately adapted to the outer profile of the spoiler. 2.The wiper blade of claim 1, characterized in that the at least oneretainer (36, 136, 236, respectively) is disposed in a longitudinalcenter portion of the support element (12) and is provided with means(52) for attaching a driven wiper arm (18).
 3. The wiper blade of claim2, characterized in that an additional retainer (38) is disposed on oneend of the support element (12) and is provided with means (54) forcovering end edges (56) of the longitudinal rails (32).
 4. The wiperblade of claim 3, characterized in that a further retainer (40) isdisposed between the retainer (36) disposed in the longitudinal centerportion and the additional retainer (38) disposed on the end of thesupport element (12).
 5. The wiper blade of claim 1, characterized inthat each retainer (36, 38, and 40, respectively), with at least oneclaw (58), clasps a respective one of the two longitudinal rails (32) ona longitudinal edges (33).
 6. The wiper blade of claim 5, characterizedin that the at least one recess (46, 48, 50, respectively), in thespoiler (23), is groove-shaped and is filled by a body (41) of the atleast one retainer.
 7. The wiper blade of claim 6, characterized in thatin terms of the length of the wiper blade (10), a length of the at leastone retainer (60 w and 62) is adapted to a length of the groove-shapedrecess (46 and 50, respectively).
 8. The wiper blade of claim 7,characterized in that the at least one retainer (236, 238, 240) isprovided with a wall (242), which extends longitudinally of the wiperblade (10) and which covers a peripheral region of the spoiler (23),adjacent to the recess, on a back wall on the spoiler, remote from aleading-edge face (44).
 9. The wiper blade of claim 8, characterized inthat the body (41) of the at least one retainer (136 and 138), on itsface end toward a recess wall of the spoiler (23), is provided with arecess (137 and 139, respectively), into which the spoiler (23) plungeswith a respective end piece (141 and 142).
 10. The wiper blade of claim1, characterized in that the at least one retainer (36, 38, 40; 136,138, 140; 236, 238, 240) is made from a plastic.